<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<div style="clear: both">
<div style="float:left; width:10px; background-color:red">&nbsp;</div>
<div style="float:left;">
<label><input type="checkbox"></input>
Kiến thức phổ thông</label></div>
</div>
<div style="clear: both">
<div style="margin-left:50px">
<input type="checkbox"></input>
Toán học

<div style="margin-left:50px">
<input type="checkbox"></input>
Vật lí</div>
</div>

</div>

</div>
<div style="clear: both">
<div style="float:left; width:50px; background-color:red">&nbsp;</div>
<div style="float:left;">
<input type="checkbox"></input>
Hóa học</div>
</div>
<div style="clear: both">
<div style="float:left; width:50px; background-color:red">&nbsp;</div>
<div style="float:left;">
<input type="checkbox"></input>
Sinh học</div>
</div>
</body>
</html>